Lightning’s impact on forests’ big trees

MILLBROOK — There was a time when trees were thought of mostly for building shelter or providing fuel, for warmth, light or cooking.

Today, trees are the subject of research and study through  many programs at the Cary Institute of Ecosystem Studies. On Thursday, Oct. 20, one of its scientists discussed the impact of lightning on tropical forests, what the future holds for those forests and what it could mean for the Northern Hemisphere.

Cary’s President, Josh Ginsberg, had the conversation with Evan Gora, who holds a doctorate in Forest Ecology from the University of Louisville. His specialties cover plant death and decomposition, as well as the causes of death, such as lightning. Gora, a Cary scientist, is an Earl S. Tupper Fellow and works with Smithsonian Tropical Research Institute, Balboa, Ancon, Panama.

The studies are taking place in Latin America, Rwanda, Brazil, Uganda, Panama  and the Dominican Republic. Scientists, ecologists, tropical ecologists are researching and studying the trees in these forests due to the fact that many of these trees are very old, some as much as 1500 years, and others even older.

They are also large trees, and so have the biggest impact on the land that surrounds them. One of the most important functions of trees is in providing carbon storage.

This conversation was mainly concerned with how the very large and very old trees fare during climate change, as massive lightning strikes have become in some instances more frequent, and in some cases more intense. The older a tree is, the larger it is, the more carbon storage it provides. So each tree lost adds up to a large amount of carbon storage loss, and is a big influence on the ecosystem processes.

The study of these losses in the tropical forests will allow scientists to follow patterns, and to understand the importance of the morbidity of trees in the ecosystem,  and enabling some predictions about the future of the forests.

The studies examine why trees die, how and when they decompose, what the conditions are that determine this.

The reason studying lightning strikes is so beneficial to the studies is because the lightning hit on one tree can mean the death of many trees. The largest and tallest tree, the canopy tree, can take down surrounding trees along with catching fire itself. Lightning flows outward. It may kill five trees and damage as many as 18 trees — a significant amount of carbon storage gone.

Gora said that lightning strikes are hard to predict and just as hard to locate. But with climate change, some areas have seen accelerated events.  Central Africa has seen a rise of about 50%. It has been estimated that in New York, by 2050, carbon storage will decrease by 25% to 50%.

One method of finding the strikes is through the use of drones. Information gathered can be used to plan the planting of future forests. By knowing the causes of death, the trees best suited to withstand lightning strikes and other hazards, newly planted forest can be planned to last longer and be safer from the usual causes of tree death.

Gora  points out that there has been little investment made in tropical forests, and the study of tropical forests can be useful in helping to understand our local forests and their problems.

Studying tropical forests also can help in the planning of reforesting our own local forests. Lightning strikes are similar around the world, and they are massively misunderstood.

What can we do locally to help our forests to thrive, and reduce the carbon impact? Gora had some suggestions: minimize your impact by reducing your carbon footprint and offset the rest by decreasing your consumption of beef and palm oil.  He also suggests supporting science by investing in the research needed to guide resilient management and reforestation. Lastly, he said, use your voice  to advocate for the protection of old growth forests.